diff options
Diffstat (limited to 'arch/x86/kvm/mmu/spte.c')
| -rw-r--r-- | arch/x86/kvm/mmu/spte.c | 68 |
1 files changed, 47 insertions, 21 deletions
diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c index 0f9f47b4ab0e..df31039b5d63 100644 --- a/arch/x86/kvm/mmu/spte.c +++ b/arch/x86/kvm/mmu/spte.c @@ -37,7 +37,6 @@ u64 __read_mostly shadow_mmio_value; u64 __read_mostly shadow_mmio_mask; u64 __read_mostly shadow_mmio_access_mask; u64 __read_mostly shadow_present_mask; -u64 __read_mostly shadow_memtype_mask; u64 __read_mostly shadow_me_value; u64 __read_mostly shadow_me_mask; u64 __read_mostly shadow_acc_track_mask; @@ -96,8 +95,6 @@ u64 make_mmio_spte(struct kvm_vcpu *vcpu, u64 gfn, unsigned int access) u64 spte = generation_mmio_spte_mask(gen); u64 gpa = gfn << PAGE_SHIFT; - WARN_ON_ONCE(!vcpu->kvm->arch.shadow_mmio_value); - access &= shadow_mmio_access_mask; spte |= vcpu->kvm->arch.shadow_mmio_value | access; spte |= gpa | shadow_nonpresent_or_rsvd_mask; @@ -107,7 +104,7 @@ u64 make_mmio_spte(struct kvm_vcpu *vcpu, u64 gfn, unsigned int access) return spte; } -static bool kvm_is_mmio_pfn(kvm_pfn_t pfn) +static bool __kvm_is_mmio_pfn(kvm_pfn_t pfn) { if (pfn_valid(pfn)) return !is_zero_pfn(pfn) && PageReserved(pfn_to_page(pfn)) && @@ -128,6 +125,35 @@ static bool kvm_is_mmio_pfn(kvm_pfn_t pfn) E820_TYPE_RAM); } +static bool kvm_is_mmio_pfn(kvm_pfn_t pfn, int *is_host_mmio) +{ + /* + * Determining if a PFN is host MMIO is relative expensive. Cache the + * result locally (in the sole caller) to avoid doing the full query + * multiple times when creating a single SPTE. + */ + if (*is_host_mmio < 0) + *is_host_mmio = __kvm_is_mmio_pfn(pfn); + + return *is_host_mmio; +} + +static void kvm_track_host_mmio_mapping(struct kvm_vcpu *vcpu) +{ + struct kvm_mmu_page *root = root_to_sp(vcpu->arch.mmu->root.hpa); + + if (root) + WRITE_ONCE(root->has_mapped_host_mmio, true); + else + WRITE_ONCE(vcpu->kvm->arch.has_mapped_host_mmio, true); + + /* + * Force vCPUs to exit and flush CPU buffers if the vCPU is using the + * affected root(s). + */ + kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_OUTSIDE_GUEST_MODE); +} + /* * Returns true if the SPTE needs to be updated atomically due to having bits * that may be changed without holding mmu_lock, and for which KVM must not @@ -165,6 +191,7 @@ bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, { int level = sp->role.level; u64 spte = SPTE_MMU_PRESENT_MASK; + int is_host_mmio = -1; bool wrprot = false; /* @@ -177,7 +204,7 @@ bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, if (sp->role.ad_disabled) spte |= SPTE_TDP_AD_DISABLED; - else if (kvm_mmu_page_ad_need_write_protect(sp)) + else if (kvm_mmu_page_ad_need_write_protect(vcpu->kvm, sp)) spte |= SPTE_TDP_AD_WRPROT_ONLY; spte |= shadow_present_mask; @@ -212,15 +239,15 @@ bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, if (level > PG_LEVEL_4K) spte |= PT_PAGE_SIZE_MASK; - if (shadow_memtype_mask) + if (kvm_x86_ops.get_mt_mask) spte |= kvm_x86_call(get_mt_mask)(vcpu, gfn, - kvm_is_mmio_pfn(pfn)); + kvm_is_mmio_pfn(pfn, &is_host_mmio)); if (host_writable) spte |= shadow_host_writable_mask; else pte_access &= ~ACC_WRITE_MASK; - if (shadow_me_value && !kvm_is_mmio_pfn(pfn)) + if (shadow_me_value && !kvm_is_mmio_pfn(pfn, &is_host_mmio)) spte |= shadow_me_value; spte |= (u64)pfn << PAGE_SHIFT; @@ -265,6 +292,11 @@ bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, mark_page_dirty_in_slot(vcpu->kvm, slot, gfn); } + if (static_branch_unlikely(&cpu_buf_vm_clear) && + !kvm_vcpu_can_access_host_mmio(vcpu) && + kvm_is_mmio_pfn(pfn, &is_host_mmio)) + kvm_track_host_mmio_mapping(vcpu); + *new_spte = spte; return wrprot; } @@ -440,6 +472,12 @@ void kvm_mmu_set_mmio_spte_mask(u64 mmio_value, u64 mmio_mask, u64 access_mask) } EXPORT_SYMBOL_GPL(kvm_mmu_set_mmio_spte_mask); +void kvm_mmu_set_mmio_spte_value(struct kvm *kvm, u64 mmio_value) +{ + kvm->arch.shadow_mmio_value = mmio_value; +} +EXPORT_SYMBOL_GPL(kvm_mmu_set_mmio_spte_value); + void kvm_mmu_set_me_spte_mask(u64 me_value, u64 me_mask) { /* shadow_me_value must be a subset of shadow_me_mask */ @@ -463,13 +501,7 @@ void kvm_mmu_set_ept_masks(bool has_ad_bits, bool has_exec_only) /* VMX_EPT_SUPPRESS_VE_BIT is needed for W or X violation. */ shadow_present_mask = (has_exec_only ? 0ull : VMX_EPT_READABLE_MASK) | VMX_EPT_SUPPRESS_VE_BIT; - /* - * EPT overrides the host MTRRs, and so KVM must program the desired - * memtype directly into the SPTEs. Note, this mask is just the mask - * of all bits that factor into the memtype, the actual memtype must be - * dynamically calculated, e.g. to ensure host MMIO is mapped UC. - */ - shadow_memtype_mask = VMX_EPT_MT_MASK | VMX_EPT_IPAT_BIT; + shadow_acc_track_mask = VMX_EPT_RWX_MASK; shadow_host_writable_mask = EPT_SPTE_HOST_WRITABLE; shadow_mmu_writable_mask = EPT_SPTE_MMU_WRITABLE; @@ -521,12 +553,6 @@ void kvm_mmu_reset_all_pte_masks(void) shadow_x_mask = 0; shadow_present_mask = PT_PRESENT_MASK; - /* - * For shadow paging and NPT, KVM uses PAT entry '0' to encode WB - * memtype in the SPTEs, i.e. relies on host MTRRs to provide the - * correct memtype (WB is the "weakest" memtype). - */ - shadow_memtype_mask = 0; shadow_acc_track_mask = 0; shadow_me_mask = 0; shadow_me_value = 0; |